VIEW ANSWER FOR PART ONE :
DEMAND AND SUPPLY , OFFER CURVES, AND THE TERMS OF TRADE

a. The former but not the latter can be used to determine the equilibrium price with trade

b. the former but not the latter can be used to determine the equilibrium quantity with trade

c. the former but not the latter takes into consideration the interaction among all markets in the economy

*d. the former gives only an approximation to the answer sought.